On machines for producing hollow glass articles, particularly bottles, the bottles produced on each line are transferred from the relative finishing mold onto a relative horizontal supporting plate or surface, from which they are transferred onto an unloading conveyor by means of a push device which moves the bottles along a 90° arc.
The push device comprises a comblike transfer member having one or more compartments, each for housing a respective bottle and bounded by a rear wall and a lateral wall crosswise to the rear wall. As the transfer member rotates along said arc, each bottle is retained inside the respective compartment by a stream of compressed air issuing from an opening normally located at a free end of the lateral wall of the compartment and oriented to produce a stream of retaining air parallel to the supporting plate and directed onto a bottom portion of the bottle to force the bottle into the corner formed by the rear wall and the lateral wall.
Though adopted, some known solutions fail to provide for retaining the bottle inside the compartment regardless of the shape/size of the bottle and the initial position of the bottle with respect to the transfer member. Whereas, in others, the air blown onto the bottle damages the outer surface of the bottle, thus reducing the quality of the finished product. Serious problems arise, in particular, when the conveyor belt exceeds a given threshold speed, e.g. fifty metres a minute; in which case, the article is transferred at such a rotation speed that the centrifugal force acting on the article is greater than the friction between the article and the supporting surface, with the result that the article is spun off the transfer member.